Panhellenism during classical ages was a political ideology supporting the belief that the Greek cities could solve their political, social, and economic problems by uniting in common cause and conquering all or part of the mighty Persian Empire. Although the origins of panhellenism should be found in 5th century, it was during the 4th century it reached its peak. Beginning with the Olympic Oration of Gorgias (408 or 392 according to others) and a little later with Lysias (probably 388 BC), it was finally culminated later with Isocrates. In his Panegyricus, Isocrates argued that Athens and Sparta together should share the hegemony. However he later hoped that a single leader, such as Philip of Macedon, could first reconcile and then lead the united Greeks in the great crusade. In accordance during the summer of 337 Philip of Macedon summoned delegates from various Greek states to Corinth. He established there a permanent seat the so-called League of Corinth, an organization which was surely meant both to recall and to be the successor of the Hellenic League of 480. These delegates, after Philip’s suggestion, declared war on Persia with Philip himself as supreme commander. Philip’s assasination a little later paused for a while Macedonian plans for the Asian expedition which was destined to be fulfilled by his son Alexander.

Here we have to acknowledge there were also attempts in the past of ambitius Greek leaders to unite Greeks against their common enemy, the Persians. When the Spartan king Agesilaus invaded Asia in 396 he was greatly admired, according to Xenophon (Ages. 1. 8), because he desired to requite the King of Persia for his ancestor’s previous invasion of Greece. He also wished to gain independence for the Greek cities in Asia. When first Philip and then Alexander announced their intention of invading Asia, they employed the very same justification as had Agesilaus. This was to free the Greeks in Asia from Persian rule and to punish the Persians for their invasion of Greece in 480. Ironically Agesilaus evenif he was successful in the beginning of his Asian adventure had to cancel a little later his Asian expedition after he was recalled to defend Sparta in 394 because the most powerful of the Greek states (Athens, Argos, Thebes, and Corinth) were quick to fight against Sparta with Persian money. Spartan army and navy had to fight at certain occasions a united Persian-Greek army (ie Battle of Knidus).

Here we must understand the vast majority of Greeks were not “thrilled” with the idea of concentration of power to a single person. Bringing back to mind the case of Jason of Pherae, despite Isocrates claim (Phil. 119.20) that he “obtained the greatest reputation” by merely proclaiming that he intended to cross over to Asia and make war upon the King, in fact JAson was so dreaded by the Greeks that in 370 his assassins were honoured in most of the cities which they entered. This was a clear proof, in Xenophon’s opinion (Hell. 6. 4. 32), of how much the Greeks feared that Jason would become their tyrant. It was these suspicions that Greeks had felt for Jason which forced Philip to stress that he wasnt their tyrant but instead their Leader and avenger.

After the assasination of Philip, his successor to the throne of Macedon, Alexander managed to fulfil his father’s plans. Lets analyze what position had Panhellenism in Alexander’s campaign. In the beginning of his expedition Alexander showed to everybody the Panhellenic character of his campaign.

– In his letter to Darius in 332 BC, as reported by Arrian, Alexander subtly weaves together Greek and Macedonian grievances (2. 14. 5.6): “Your ancestors invaded Macedonia and the rest of Greece and did us great harm, although you had suffered no prior injury; I have been appointed hegemon of the Greeks and have invaded Asia in the desire to take vengeance on the Persians for the aggressions which you began.”

– When he reached the Hellespont he sacrificed at the tomb of Protesilaus at Elaeus, who was the first of the Achaeans to be killed during the Trojan War. Right after, in imitation of Protesilaus, he was the first to leap ashore onto Asian soil. As soon as he crossed he proceeded to Troy, where he sacrificed in the temple of Athena and exchanged his own armour for a set dating from the Trojan War. Those arms were always carried before him in battle. He also crowned the tomb of Achilles and performed other ceremonies there. Xerxes had sacrificed at Troy before invading Greece and so it was only to be expected that Alexander would do likewise before invading Asia. After the battle of the Granicus, Alexander sent 300 Persian panoplies to Athens as a dedication to Athena (Arr.1. 16. 7; Plut. Alex. 16. 17.18). The inscription attached to the dedication was pointed: OAlexander the son of Philip and the Greeks except the Lacedaemonians from the barbarians who dwell in Asia. During the battle of the Granicus, Alexander slaughtered most of the 20,000 Greek mercenaries who fought for the Persians and dispatched some 2,000 of them as prisoners to Macedonia, where they would be subject to hard labour. His justification, as Arrian (1. 16. 6) explains, was because though being Greeks, in violation of the common resolutions of the Greeks, they had fought against Greece for barbarians. Alexander then proceeded, although with some flexibility on his part, to keep his word and liberate the Greek cities of Asia.

– While en route from Miletus to Caria he proclaimed that he had undertaken the war against the Persians for the sake of the freedom of the Greeks (Diod. 17. 24. 1: cf. Arr. 1. 18. 1.2). Later, in Lycia near the city of Xanthus, Alexander was encouraged by the discovery of a bronze tablet which allegedly predicted the destruction of the Persian Empire by Greeks. Decades ago, Cimon, the son of Miltiades according to Plutarch (Cimon 18. 7) sent messengers to the shrine of Ammon to consult the god during operations against the Persian empire. After his conquest of Egypt, Alexander followed the example of the famous Greek leader Cimon and consulted the oracle of Zeus Ammon. Perhaps Alexander may have wanted the Athenians and other Greeks to see him as completing the task which Cimon had begun more than a century earlier.

– Before the battle of Issus, Alexander encouraged his Greek forces with the appropriate panhellenic themes. Curtius (3. 10) and Justin (11. 9. 3.6) claim that Alexander said what was appropriate to each of the nationalities in his
army and give a similar account of what he said to the Greeks. To quote Justin: Ohe rode round his troops addressing remarks tailored to each nationality among them and he Oinspired the Greeks by reminding them of past wars and of their deadly hatred for the Persians The battle of Gaugamela was nothing short of a panhellenist set piece. As Plutarch
describes it (Alex. 33. 1), before the battle Alexander made a very long speech to the Thessalians and the other Greeks and when they encouraged him with shouts to lead them against the barbarians, he shifted his spear into his left hand and with his right he called upon the gods, as Callisthenes says, praying to them, if indeed he was truly sprung from Zeus, to defend and strengthen the Greeks.

– Following the battle Alexander took steps seeking, as Plutarch (Alex. 34) says, to win the favour of the Greeks. He wrote to them that the tyrannies had been abolished (meaning those in Asia) and that the Greeks were autonomous. He wrote separately to the Plataeans that he would rebuild Plataea because their ancestors had furnished territory to the Greeks
for the struggle on behalf of their freedom. He also sent a portion of the spoils to the people of Croton because the athlete Phayllus had fitted out a ship at his own expense with which he fought at Salamis in 480 (Plut. Alex. 34). In this way Alexander, always mindful of the significant gesture, linked his victory at Gaugamela with the Greek victories at both Plataea and Salamis.

– As Alexander proceeded eastwards, more gestures followed. After the capture of Susa in 331 he sent (or promised to send) back to Athens the bronze statues of Harmodius and Aristogeiton and the seated figure of Artemis Celcaea which Xerxes had removed (Arr. 3. 16.7.8); something which he may actually have done in 324 (Arr. 7. 19. 2)

– Finally, we have the burning of Persepolis. When Alexander first arrived he handed over the city proper, apart from the palace complex, to be sacked by his troops. According to the vulgate tradition, Alexander proclaimed that Persepolis was the most hostile city in Asia and should be destroyed in retaliation for the invasions of Xerxes and Darius. Alexander then wintered at the palace complex and Plutarch claims that when Demaratus the Corinthian, who had been a friend of Philip’s, saw Alexander seated on the throne of Darius, he said that Othose Greeks were deprived of great pleasure who had died before seeing Alexander seated on that throne. None the less, at the end of his sojourn, the palace was destroyed. The official explanation for this act of terrorism is provided by Arrian (3. 18. 12; cf. Strabo 15. 3. 6): that Alexander wished to punish the Persians for their invasion of Greece, the destruction of Athens, the burning of the temples, and for all their other crimes against the Greeks.

– Because Alexander soon disbanded his allied contingents at Ecbatana in 330 (Arr. 3. 19. 5.6; cf. Diod. 17. 74. 3; Curt. 6. 2. 15.17), it is generally asserted that the panhellenic part of the expedition was over. But this was not true for several reasons and it should be emphasized that no ancient source marks this as a turning point. First of all, to Alexander’s panhellenic audience in Greece the burning indeed would have signalled that the destruction of Athens had been avenged, but it would not obviously have signalled the end of the panhellenic campaign. Isocrates had urged Philip (Phil. 154) Oto rule as many of the barbarians as possible and Alexander still had a long way to go in order to fulfil that recommendation. Secondly, Arrian says that not a few of the Greek troops stayed on as mercenaries, and this may have been Alexander’s way of transferring the cost of their maintenance from their home cities to himself in the wake of his seizure of the Persian royal treasuries.

– an incident took place in the summer of 329 that unequivocally demonstrates that the war of revenge was still being employed. Curtius narrates in vivid detail how Alexander, after he had crossed the Oxus river, came upon a small town in Bactria, inhabited by the Branchidae. These Branchidae, Curtius tells us, were the descendants of the priests who had violated the temple of Apollo at Didyma and betrayed it to Xerxes in 479. lexander took a terrible revenge upon them for their ancestors’ treachery: the Branchidae were massacred as traitors and their town was destroyed root and branch.

– During 326 BC, when he was crossing the river Hydaspes in a storm just before his battle with Porus, according to Onesicritus, Alexander cried out OOh Athenians, could you possibly believe what sort of dangers I am undergoing in order to win a good reputation in your eyes.

– During the winter of 325/4 BC the historian Theopompus of Chios wrote a letter to Alexander in which he laments that although Harpalus had spent more than two hundred talents on memorials for his deceased mistress, no one had yet adorned the grave of those who died in Cilicia on behalf of your kingship and the freedom of the Greeks.This does not demonstrate that Theopompus was himself a panhellenist but rather, it indicates that a Greek on the island f Chios, who was trying to ingratiate himself, thought that
Othe freedom of the Greeks of Asia was still an important slogan to Alexander. Many of those cities must have felt that Alexander was sincere enough, since they not only granted him divine honours, but maintained his cult for centuries after his death.

– we have Diodorus’ description of the funeral pyre of Hephaestion, which was no doubt designed by Alexander himself. Hephaestion died in the autumn of 324, after the marriages at Susa and the banquet of reconciliation at Opis. Diodorus (17. 115. 4) says of the pyre, which must have looked like a ziggurat, that the first level was decorated with the prows of 240 quinqueremes, each bearing two kneeling archers and armed male figures; this, we can infer, alluded to the battle of Salamis. The fourth level, he tells us, carried a centauromachy rendered in gold and the sixth level was covered with Macedonian and Persian arms, Osignifying the bravery of the one people and the defeats of the other. The centauromachy, in particular, was surely meant to evoke the Greek/barbarian antithesis of fifth-century Athenian public monuments .

You can click on the links in the body of the letter and it will send you where you need to go for information taken from the mouth of world scholars on the matter. Also there are various articles around Alexander in this blog.